Resinifying hydroxyl formyl acetophenones, acetoxy benzaldehydes, and methoxy derivatves thereof



Patented Dec. 25, 1951 RESINIFYING HYDROXYL FORMYL ACETO- PHENONES, ACETOXY BENZALDEHYDES, AND METHOXY DERIVATIVES THEREOF Alfred Russell, deceased, late of Cincinnati, Ohio, 16: Chester lt. Shook, administrator, Cincinnati,

No Drawing. Application September 18, 1948, Serial No. 5.,234

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 6 Claim.

This application is made under the act of 30, 1928, and the invention herein described, if patented, may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to me of any royalty thereon.

This invention relates to a new class of polymeric materials and to novel processes for producing them. In particular, it relates to polymeric materials obtained by causing certain bi- -functiona1 keto-aldehydes, or their chemical equivalents, to undergo polymerization by interaction between like molecules.

The invention has among its objects provision of a new class of products capable of varied and novel uses and methods for producingthem from readily available raw materials.

Polymerization may be defined as that type of chemical reaction that is functionally capable of proceeding indefinitely. This invention is based upon the discovery that compounds of the gen eral formula: 1

RI OHC-XC 00 1i RII will undergo polymerization. R and R" are hydrogen or organic radicals attached by carbon to carbon linkage, and X is a divalent organic radical. As will be explained below, the invention is not limited to the polymerization of compounds of this type, but valsoincludes equivalent compounds or combinations of substances which yield the keto-aldehydes under the conditions oi the reaction. In general, the keto-aldehydes react very readily, and it is therefore usually more convenient to employ the aforesaid equivalents. The equivalents may be classified in general as: (1) Chemicals or combinations of chemicals which result in the introduction of a keto group into the molecule containing an aldehyde group. (2) The introduction of an aldehyde group into a molecule already containing a keto group.

Examples of the first instance are vanillin monacetate, which in the presence of A101: can be made to yield 2-hydroxy-3-methoxy-5-formylacetophenone, i. e., specific applications of the well-known Fries rearrangement. Furfural and 'acetyl chloride may be caused to react producing In the formula given above the bifunctional keto-aldehydes may be aliphatic, aromatic, or heterocyclic in character. The X may be any suitable divalent radical, aliphatic or aromatic in character, while the R and R." may be hydrogen or organic radicals.

Due to the reactivity of the keto-aldehydes, they are not usually isolated as such but are formed in situ in the reaction zone, and straightway polymerize to yield the products of this invention. The invention is not limited to such procedure, however, but contemplates also the polymerization of the isolated monomeric ketcaldehydes. In general, the structure of the products may be characterized as (1) direct addition products; (2) polymeric alpha, beta-unsaturated ketones, or (3) ketones in which the original character of the polymerizing molecule has been modified, for example, by subsequent ring closure.

From the foregoing it may be seen that a variety of structural configurations are included in the products of this invention. With reference to the above formula the following conflgurations may be produced through polymerization of the keto-aldehydes or their equivalents.

(1) The direct addition products have the following structure:

(2) If either R or R" are hydrogen atoms, the preliminary addition reaction may be followed by subsequent loss of water to give the following structure:

If both R. and R" are hydrogen atoms, the preliminary addition reaction may be followed by subsequent loss of water to give products of the following structure:

. XCH=CHCOXCH CHCOXCH==CHCO- (3) If, in addition, these two latter cases also contain an aromatic radical in the X position which in turn is substituted by a suitable reacting group, such as hYCilOlQ l, ortho to the keto group, the character of the polymerized product may be further modified by subsequent ring closure to give products of the following structure:

CO 0 GO In several of the products it has been dissteam distillation. The reaction product is a covered that conditions of equilibrium occasiondark colored amorphous powder. ally exist between polymers having a structure The initial reaction involves a Price rearrangerepresented by the second group and those reprement as toilows:

sented by the third group. or that one may be converted into the other by suitable reaction 000cm on conditions. For example, under alkaline condi- A101;

tions the straight line structure of polymer (2) is CEO CH Coca maintained, whereas in the presence of acid the ring-closed polymer (3) predominates. The resulting keto-aldehyde undergoes polymer- In general, the products of this invention are ization in situ to form a polymeric product havamorphous hygroscopic resins, varying in color ing the following structural formula:

OCH:

on com com com on on on c oon=cn c ocn=cn oocn=cn cocn=c-.

(aikalDI 1 (acid) OCH: 0 OCH: 0

from light fawn to dark brown. They are gen- This product tends to occur in the open chain erally insoluble in the common organic solvents. form under alkaline conditions, while in the pres- As illustrated in the examples below, several of ence of acid the ring-closed form predominates. the polymers are similar in structure to natural This product, a poly-8-methoxydihydrobenzolignins. pyrone, has all the significant physical character- The products are useful as soil conditioning istics and chemical properties of natural gymnoagents, extenders for plastics and molding comspern or spruce lignin. Quantitative comparison positions, film-forming compositions, adhesives by analysis and analysis of derivatives indicate and the like. They may be solubilized, for exthe so-called gymnospern or spruce lignin and ample by sulfonation and thus may be used for this synthetic product to be identical. Like the above purposes and for such additional purnatural lignin this product dissolves on warming poses as tanning agents and the like. with aqueous sodium bisuifite. Dispersed on fil- Ingeneral, the polymerization proceeds readily ter paper the product gives a pink color with and all that is necessary is to provide chemical phloroglucinol dissolved in 12 percent aqueous contact between molecules of the monomeric hydrochloric acid. keto-aldehyde. The polymerization reaction re- Example 2 sponds to the usual acidic polymerization catalysts, and its speed may be increased by heating. e xy oldehyde (10 8-) is dissolved The usual condensing agents may be used to in of dry nitrobenzene, and 18 s. f yaccelerate the reaction, such as anhydrous AlCis. dmus aluminum chloride a d Th reaction ferric chloride, zinc chloride, sulfuric acid and m xture is heated on a steam bath at -70 C. the like. It is convenient but not essentialtouse 50 f r 2 hrs- The resulting reaction mixture is inert solvents inthe polymerization reaction. P d into dilute hydrochloric acid. n e

The temperatures 01 reaction are not critical, nitrobenzene r v d y steam i ti lation. The and it may be carried out at room temperature p y e p o ct s a pink colored amorphous or at elevated temperature. With lower tem- P w rperatures, longer times are required. 55 Example 3 The molecular weight or extent or polymeriza- San laldeh d n tion of the new products is not known. Theyv g g 8333:22 3 are probably molecular mixtures of varying anhydrous aluminum chloride addea The length. Nevertheless, there are indications that tion mixture is heated to for one those a such as ExamPle hfwmg 60 hour and the product is recovered as in Examples tures similar to natural lignm consist of mole- 1 and The product is a fawn colored amok cules of more uniform molecular weight than the phous powden natural products. Example 4 The following specific examples illustrate the invention, but are not to be considered as as Anhydmlls aluminum chloride (53-2 8- 18 8118- n tm pended in 500 cc. dry carbon disulilde, and 31.4 ll.

Example 1 acetyl chloride is added. The mixture is cooled with ice and 38.4 g. i-urfural dissolved in 100 cc.

9.7 g. o! vanillin monoacetate is dissolved in carbon disulfide is added with stirring over a 50 g. dry nitrobenzene and 13.3 g. of anhydrous 7 period of 25 minutes. The reaction mixture was aluminum chloride added. This reaction mixkept cool and stirred for about four hours, and ture is heated to C. and the temperature then allowed to stand overnight. The dark reheld at this value for 1 hr. The resulting reacaction product is resinous at first and gradually tion mixture is then treated with dilute hydrobecomes friable. Hydrogen chloride is evolved chloric acid, and the nitrobenzene removed by 75 during the reaction. The whole reaction mixthe solution heated to boiling for about twenty 6 ture is then poured into ice water and the carortho and para to the CH group, dissolved in bon disulfide layer separated. a volatile solvent in the presence of an. acidic con- The dark solid reaction product remains susdensing agent to form a water-insoluble conpended in the water layer. It is collected, densation product and isolating said product crushed, washed with dilute hydrochloric acid, from the reaction mixture. washed again with water, with alcohol and with 2. A process comprising heating to at least ether, and finally dried. 60 C. 2,4-dihydroxy-3-formyl-acetophenone dis- The reaction of this example illustrates the solved in a volatile solvent in the presence of an formation in situ of an evanescent keto-aldehyde acidic condensing agent to form a water-insoluand the subsequent immediate formation of the ble condensation product and isolating said prodpolymer. not from the reaction mixture.

. UCOCH=CHU-COCH=CHU COCH=CH Example 5 3. A process as in claim 1 wherein the aceto- In the previous examples the keto a1dehydes phenone derivative has been formed in situ by are formed in the reaction mixture and poly- FXies reaction merized at once under the reaction conditions. process comprising heatmg to at least 60 C. salicylaldehyde monoacetate dissolved in k de fi gfi gsg zk :23 a fig z i g hyde 1s a volatile solvent in the presence of aluminum chloride to form a water-insoluble condensation 33 1 gg ggfzfiggzgfigz zggi product and isolating said product from the reis cooled in a Dry Ice bath and 23 g. dry zinc 25 acuon mlxturecyanide added, followed by 26 g. anhydrous alu- A process comprising i at least mmum chloride dissolved in 100 dry ether 60 C. vanillin monoacetate dissolved m a vola- Dry hydrogen chloride gas is passed into the cold tile solvent in thepresence of aluminum chloride solution to saturation (4-7 hours). and the preto a water'msoluble condensatlonProdilct cipitated solid collected and Washed with dry 30 :Jld isolating said product from the reaction mixether. It 18 then dissolved in 100 cc. water and 6. A process comprising heating to at least minutes. An oil is separated out, and is collect- 19- pam'acetoxybenzaldehyde dissolved in a This quickly solidifies and is recrystallized volatile solventinthe presence of aluminum chlofrom a mixture of alcohol and water. It is ride to form a water-insoluble condensation identified as 24 dihydmxy 3 formylacetophe product and isolating said product from the renone by description and melting point. action i For the polymerization, 5 g. of the above keto- CHESTER SHOCK- aldehyde is dissolved m 100 cc. ethanol and 75 cc. Admmsmt" of the Estate of Alfred Russell concentrated sulfuric acid added. The whole is Deceasedrefluxed for thirty minutes, cooled and poured into water. The product is a bright red amorphous solid.

What is claimed is:

1. A process comprising heating to at least C. a 'i'ormyl acetophenone derivative of the formula REFERENCES CITED The following references are of record in the file of this patent:

Claisen et al.: Berichte Deut. Chem. Gesel., vol. 22, 1889, pp. 3273, 3274, 3275.

Freudenberg: Liebigs Annalen der Chemie,

R0). OH vol. 510, pp. 206, 212, 213.

Organic. Reactions, vol. I, Wiley, 1942, pp. 342 and 343; article by Blatt. one coon, Shah et al.: J. Chemical Society (London),

1938 pp. 1828-1830. wherein R is selected from the group consisting Shah et a1.:. J. Chemical Society (London), or hydrogen and methyl and wherein n is a whole 5 1 pp- 1 2 and 1 number from 0 to 1, and in which compound the Russell: Jour. Amer. Chem. S0c., v01. 70. PP- indicatecl OH group is in one oi. the positions 2864 and 2865. 1948. 

1. A PROCESS COMPRISING HEATING TO AT LEAST 60* C. A FORMYL ACETOPHENONE DERIVATIVE OF THE FORMULA 